What is the .tar.gz File Extension?
.tar.gz is a file extension associated with gzipped tarball archives, which are zipped folders commonly found on Linux, but rarely used on Windows. More specifically, the .tar extension is associated with tarballs, while the additional .gz suffix is added to files that were compressed using a program called gzip, which is commonly found installed by default on many Linux distros.
How to Open .tar.gz Files?
.tar.gz files can be opened directly by Windows 11's file manager (the File Explorer). On previous versions of Windows, this wasn't possible, so an archiver with .tar.gz support such as WinRAR or 7-Zip had to be installed.
Warning: if you are on Windows and you aren't downloading the source code of an application that is open source, it's very likely you downloaded the wrong file. .tar.gz files aren't normally used to distribute applications to Windows users. Perhaps you were supposed to download a .zip file instead.